The Company has the following convertible notes payable outstanding as of March 31, 2016 and December 31, 2015:

As of March 31, 2016, scheduled principle payments due on convertible notes payable are as follows:

From April 26, 2012 to January 24, 2013, the Company sold convertible notes to unaffiliated accredited investors totaling $2,675,244. The notes have a term of three years, bear interest at 12% per annum, and are convertible into units, where each unit consists of: (i) one share of common stock of the Issuer, par value $0.001 per share, and (ii) a warrant to purchase 0.25 shares of common stock of the Issuer at an exercise price of $1.25 per share. The initial conversion ratio shall be equal to $1.00 per unit. The notes may be converted at the option of the holder at any time and from time to time in whole or in part prior to the maturity date thereof. These securities were sold in reliance upon the exemption provided by Section 4(2) of the Securities Act and the safe harbor of Rule 506 under Regulation D promulgated under the Securities Act. Interest expense for the quarters ended March 31, 2016 and 2015, was $11,368 and $105,127, respectively.

During the year ended December 31, 2015, the Company and certain holders of these notes have entered into amendments which (i) extend the maturity dates by 12 months from their original maturity dates; (ii) reduce the conversion price from $1.00 to $0.50 per unit for a period of 45 days and $0.75 thereafter; and (iii) reduce the exercise of the warrant included in the unit from $1.25 to $1.00 per share. During the year ended December 31, 2015, the holders of these notes totaling $3,112,883 converted their notes into equity of the Company. The Company has converted this balance and along with accrued interest of $124,352 into 6,474,717 shares of common stock and 1,618,680 warrants to purchase common stock. The Company recognized a non-cash inducement expense of $1,123,380 associated with these conversions as they took place during the initial 45 day period after the amendment, prior to the conversion rate resetting to $0.75. As of March 31, 2016 and December 31, 2015, total principal of $378,932 and $357,483, respectively, was outstanding on these notes to the remaining note holders that did not convert.

From April 5 through May 10, 2013, the Company sold convertible notes to unaffiliated accredited investors totaling $405,000. The notes have a term of three years, bear interest at 12% per annum, and are convertible into units, where each unit consists of: (i) 1 share of common stock of the Issuer, par value $0.001 per share, and (ii) a warrant to purchase 0.25 shares of common stock of the Issuer at an exercise price of $0.75 per share. The initial conversion ratio shall be equal to $0.50 per unit. The notes may be converted at any time and from time to time in whole or in part prior to the maturity date thereof. These securities were sold in reliance upon the exemption provided by Section 4(2) of the Securities Act and the safe harbor of Rule 506 under Regulation D promulgated under the Securities Act. Interest expense for the quarters ended March 31, 2016 and 2015, was $16,556 and $14,735, respectively. As of March 31, 2016 and December 31, 2015, total principal of $551,862 and $520,625, respectively, was outstanding on these notes.

On June 27 and June 30, 2013, the Company converted advances payable from related parties into convertible notes totaling $1,036,195. The notes have a term of three years, bear interest at 12% per annum, and are convertible into units, where each unit consists of: (i) 1 share of common stock of the Issuer, par value $0.001 per share, and (ii) a warrant to purchase 0.25 shares of common stock of the Issuer at an exercise price of $0.75 per share. The initial conversion ratio shall be equal to $0.50 per unit. The notes may be converted at any time and from time to time in whole or in part prior to the maturity date thereof. These securities were issued in reliance upon the exemption provided by Section 4(2) of the Securities Act and the safe harbor of Rule 506 under Regulation D promulgated under the Securities Act. Interest expense for the quarters ended March 31, 2016 and 2015, was $6,826 and $6,075, respectively. As of March 31, 2016 and December 31, 2015, total principal of $227,549 and $214,668, respectively, was outstanding on these notes.

From July 30, 2013 through December 24, 2013, the Company sold convertible notes and warrants to unaffiliated accredited investors totaling $1,902,500. The notes have a term of three years, bear interest at 10% per annum, and are convertible into one share of common stock, par value $0.001 per share, with the initial conversion ratio equal to $0.50 per share. For each dollar invested, the investor received two warrants to purchase one shares of common stock of the Issuer at an exercise price of $0.75 per share. The notes may be converted at any time and from time to time in whole or in part prior to the maturity date thereof. These securities were sold in reliance upon the exemption provided by Section 4(2) of the Securities Act and the safe harbor of Rule 506 under Regulation D promulgated under the Securities Act. Subject to an allonge entered into by the noteholder agent representing this class of noteholders and the Company, the maturity date on all of these convertible notes was extended to July 31, 2018. Interest expense for the quarters ended March 31, 2016 and 2015, was $41,125 and $42,457, respectively. A discount on the notes payable of $841,342 was recorded based on the value of the warrants issued using a Black-Scholes options pricing model. Amortized interest expense for the quarters ended March 31, 2016 and March 31, 2015 on this discount was $38,032 and $37,613, respectively. As of March 31, 2016 and December 31, 2015, total principal of $1,645,000 was outstanding on these notes.

On August 14, 2014, the Company and its wholly-owned subsidiary MES, Inc. ("MES, and together with the Company, collectively the "Companies") entered into a financing agreement (the "Financing Agreement") with a newly created independent entity, AC Midwest Energy LLC (the "Lender"). Pursuant to the Financing Agreement, the Company borrowed $10,000,000 from the Lender, evidenced by a convertible note (the "Note") maturing July 31, 2018, secured by all the assets of the Companies. All the indebtedness under the Note was convertible into common stock of the Company at $1.00 per share, subject to the following adjustments: (i) an adjustment of the price per share down to $0.75 per share if the Company fails to generate EBITDA (earnings before taxes, interest, depreciation and amortization ) of at least $2,500,000 for calendar year 2015; and (ii) weighted average anti-dilution adjustments to the extent that following the issuance of the Note, the Company issues securities or rights to acquire securities at an effective purchase price below the conversion price for the Note, subject to carveouts for certain exempt issuances by the Company. Per an amendment to the Financing Agreement discussed below, the conversion price was adjusted to $0.50 per share and the adjustment to the price per share for failing to generate a certain level of EBITDA was eliminated.

The Note bears interest at 12% per annum, to be paid at the rate of: (i) 12% payment in kind or "PIK" for year one; (ii) 2% cash and 10% PIK for year two; and (iii) 12% all cash for years three and four. The PIK interest is paid by increasing the principal balance of the Note by the PIK amount. The Note cannot be prepaid without the Lender's consent before its second anniversary, and thereafter at 105% of the outstanding indebtedness evidenced by the Note, subject to the right of the Lender to convert the outstanding indebtedness to the Company's common stock prior to prepayment. Principal amortization of the Note is to begin with the first quarter following the second year of the Note at the rate of 7.5% of the original principal amount per quarter and to continue each quarter thereafter, with all unpaid interest to be due at maturity. In the event of default, the interest rate on the Note will be increased by an additional 3% per annum. The Financing Agreement contains numerous affirmative obligations and negative covenants. Interest expense for the three months ended March 31, 2016 and 2015 was $319,869 and $301,696, respectively. As of March 31, 2016 and December 31, 2015, total principal of $9,293,021 and $9,062,019, respectively, was outstanding on this note.

On March 16, 2015, the Company entered into a Waiver and Amendment to Financing Agreement, and Reaffirmation of Guaranty with AC Midwest Energy, LLC ("Amendment"). This Amendment decreased the conversion price of the convertible note and exercise price of the outstanding warrants to $0.50, respectively. The Company repaid $3,000,000 of outstanding principal on the convertible note as of the close of the Amendment. The Company agreed to new financial covenants as part of the Amendment, which included a waiver for the compliance of certain covenants in the periods prior to the date of the Amendment. In connection with the change in the conversion terms and repayment of principal, the Company incurred a loss of $2,246,105 on this date which was primarily related to accelerated amortization of the discount on convertible notes payable and is included in interest expense.

On November 16, 2015, the Companies entered into Waiver and Amendment No. 2 to Financing Agreement, and Reaffirmation of Guaranty (the "Amendment No. 2") with the Lender. Pursuant to Amendment No. 2, the Company issued a new Senior Secured Convertible Note of $600,000 ("First New Note") purchased by the Lender. In addition, Amendment No. 2 allows for two additional Senior Secured Convertible Notes totaling up to $1,400,000 (which together with the First New Note are referred to herein as the "New Notes") to be purchased by Lender during 2016 subject to certain conditions being met by both parties. All the indebtedness under the New Notes shall be convertible into common stock of the Company at $0.50 per share, subject to weighted average anti-dilution adjustments to the extent that following the issuance of the New Notes, the Company issues securities or rights to acquire securities at an effective purchase price below the conversion price for the New Notes. As of January 31, 2016, the Company's right to sell one additional New Note for $400,000 expired. The remaining $1,000,000 available with this amendment must be sold to Lender by June 30, 2016. In connection with Amendment No. 2, the Company was required to issue Drexel approximately 200,000 warrants and pay $21,000 as compensation for services rendered. This liability was settled with an amendment to the engagement letter with Drexel on February 19, 2016. These warrants were valued in accordance with FASB ASC 815-10 as liabilities using a Monte Carlo Simulation Model. The fair value of the warrant liability on the issuance date for the warrants to be issued was $55,200. These costs were recorded as debt issuance costs.

On January 28, 2016, the Company entered into Amendment No. 3 to Financing Agreement and Reaffirmation of Guaranty (the "Third Amended Financing Agreement") with Lender, pursuant to which Lender agreed to cause its bank to arrange for the issuance to a certain customer of the Company a standby letter of credit in the amount of $2,000,000 (the "Letter of Credit") to permit the Company to enter into a contract for mercury capture program with such customer. The Letter of Credit is to guarantee the Company's performance under its contract with such customer. Under the Third Amended Financing Agreement, and in consideration for the issuance of the Letter of Credit for the benefit of the Company, the Company shall pay AC Midwest a fee equal to 12.0% per annum of the amount available to be drawn under the Letter of Credit (the "Letter of Credit Fee") payable on the last day of each calendar month. No amounts were received on this letter of credit as of March 31, 2016.