Ramesh K. Sharma

Higher-alcohols biorefinery: improvement of catalyst for ethanol conversion.

The concept of a biorefinery for higher-alcohol production is to integrate ethanol and methanol formation via fermentation and biomass gasification, respectively, with, conversion of these simple alcohol intermediates into higher alcohols via the Guerbet reaction. 1-Butanol results from the selfcondensation of ethanol in this multistep reaction occurring on a single catalytic bed. Combining methanol with ethanol gives a mixture of propanol, isobutanol, and 2-methyl-1-butanol. All of these higher alcohols are usefulas solvents, chemical intermediates, and fuel additives and, consequently, have higher market values than the simple alcohol intermediates. Several new catalysts for the condensation of ethanol and alcohol mixtures to higher alcohols were designed and tested under a variety of conditions. Reactions of methanol ethanol mixtures gave as high as 100% conversion of the ethanol to form high yields of isobutanol with smaller amounts of 1-propanol, the amounts in the mixture depending on the starting mixture. The most successful catalysts are multifunctional with basic and hydrogen transfer components.

Ester fuels and chemicals from biomass

Bench-scale research demonstrated that using an efficient esterification step to integrate an ethanol with a carboxylic acid fermentation stream offers potential for producing valuable ester feedstocks and fuels. Polar organic acids from bacterial fermentations are difficult to extract and purify, but formation of the ammonium salts and their conversion to esters facilitates the purifications. An improved esterification procedure gave high yields of esters, and this method will lower the cost of ester production. Fuel characteristics have been determined for a number of ester-gasoline blends with promising results for lowering Reid vapor pressure and raising octane numbers.

Non-aqueous enzymatic solubilization of coal-derived materials

Abstract The utilization of enzymes in non-aqueous solvents was explored for the conversion of coal-derived materials to oil-soluble derivatives for use as fuels. A novel three-step process was developed: 1. (1) an initial low-severity conversion to a form that is soluble or dispersible in a polar solvent; 2. (2) formation of an alcohol substrate with a high activity for subsequent enzymatic processing; 3. (3) lipase-catalysed transesterification to a product that is soluble in hydrocarbon solvents. The process was successful for the conversion of a first-stage liquefaction product from Wyodak subbituminous coal to an acylated product, about half of which is soluble in hexane and the remainder in toluene. Coals, humic acids and several other higher-molecular-weight coal liquefaction products, such as Chemcoal, and their derivatives inhibited the lipases, and thus the alcohol intermediates from these precursors were converted in 0–5% yields to acylated products.

Subtask 3.9 - Direct Coal Liquefaction Process Development

The Energy and Environmental Research Center (EERC), in partnership with the U.S. Department of Energy (DOE) and Accelergy Corporation, an advanced fuels developer with technologies exclusively licensed from ExxonMobil, undertook Subtask 3.9 to design, build, and preliminarily operate a bench-scale direct coal liquefaction (DCL) system capable of converting 45 pounds/hour of pulverized, dried coal to a liquid suitable for upgrading to fuels and/or chemicals. Fabrication and installation of the DCL system and an accompanying distillation system for off-line fractionation of raw coal liquids into 1) a naphtha middle distillate stream for upgrading and 2) a recycle stream was completed in May 2012. Shakedown of the system was initiated in July 2012. In addition to completing fabrication of the DCL system, the project also produced a 500-milliliter sample of jet fuel derived in part from direct liquefaction of Illinois No. 6 coal, and submitted the sample to the Air Force Research Laboratory (AFRL) at Wright Patterson Air Force Base, Dayton, Ohio, for evaluation. The sample was confirmed by AFRL to be in compliance with all U.S. Air Force-prescribed alternative aviation fuel initial screening criteria.

SORBENT DEVELOPMENT FOR MERCURY CONTROL. Final topical report including semiannual for January 1, 1998 through June 30, 1998.

The US Environmental Protection Agency (EPA) draft Mercury Study Report to Congress (1) estimated anthropogenic mercury emissions to be 253 tons/yr in the US, with the majority (216 tons/yr) from combustion sources. The three main combustion sources listed were coal (72 tons/yr), medical waste incinerators (65 tons/yr), and municipal waste combustors (64 tons/yr). The emissions from both medical waste incinerators and municipal waste combustors were recently regulated, which, together with the reduction of mercury in consumer products such as batteries and fluorescent lights, has already reduced the emissions from these sources, as stated in the final EPA Mercury Report to Congress (2). EPA now estimates total point-source mercury emissions to be 158 tons/yr, with coal remaining at 72 tons/yr, while medical waste incinerators are down to 16 tons/yr and municipal waste combustors are at 30 tons/yr. Coal is now the primary source of anthropogenic mercury emissions in the US, accounting for 46%. In addition, the use of coal in the US has been increasing every year and passed the 1-billion-ton-per-year mark for the first time in 1997 (3). At the current rate of increase, coal consumption would reach 1.4 billion tons annually by the year 2020. On a worldwide basis,morexa0» the projected increase in coal usage over the next two decades in China, India, and Indonesia will dwarf the current US coal consumption level. Therefore, in the US coal will be the dominant source of mercury emissions and worldwide coal may be the cause of significantly increased mercury emissions unless an effective control strategy is implemented. However, much uncertainty remains over the most technically sound and cost-effective approach for reducing mercury emissions from coal-fired boilers, and a number of critical research needs will have to be met to develop better control (2).«xa0less