Bioenergy : Biomasses for energy production by gasification By : Bambang Dwi Argo Head of Bioprocess Technology Study Programe Department of Agricultural Engineering Faculty of Agricultural Technology University of Brawijaya

1. Introduction All living and recently living organisms, animal/plant waste, industrial and municipal waste What is Biomass? Microalgae Municipal Waste Agricultural Waste Animal Waste

Cont.. What is the potential of each of these biomass sources? NoKind of BiomassPotensial 1Rice Straw (in Asia)680 Million Ton/year 2Animal Waste15-20 kg/day 3Municipal Waste (Malang) ton/day 4Microalga120 ton Biodiesel/Ha/year

Cont……. Biomass utilization can be classified as: Biofuel (Biodiesel, ethanol) : contemporary process from biomass Biopower (Electric power and Heat) : direct firing, co firing, gasification, pyrolysis and anaerobic digestion) Bioproducts (Fertilizer, chemicals, cellulose, bio plastics, particle board etc) Biorefineries To be able to utilize biomass into useful products requires mastery of biorafinery technology

2. Technology Conversion Use for energy only Conversion technologies refer to a wide array of state-of-the- art technologies capable of converting unrecyclable solid waste into useful products, such as green fuels and renewable energy, in an environmentally beneficial way. These technologies may be thermal, chemical, biological, mechanical, or a combination of processes, but do not include incineration (waste combustion) Conversion technologies are an integral process in achieving a zero-waste goal. These technologies not only create a beneficial product but also potentially reduce greenhouse gas emissions and other air pollutants This reduction is achieved through disposal and transportation avoidance, as well as through fuel/electricity offsets

Cont…. Technology Conversion Biomass feedstock Biochemical Platform (Sugar) Combined Heat and Power, Fuels, chemicals and materials Biogas Platform (anaerobic digestion) Thermochemical Platform (Pyrolisis, gasification) Carbon Rich Chain Platform (Biodiesel)

a. Biochemical Conversion Plant matter – hemicellulose, cellulose, lignin Pretreatment Hydrolysis Sugar Fermentation

b. Biogas Platform : Anaerobic Digestion Biogas Platform – Methane CH4 Decomposition - microorganisms Anaerobic Digesters Four Main Processes Uses wastes and turns into valuable compost

c. Thermochemical Conversion Gasification, Pyrolysis, Direct Hydrothermal Liquefaction Carbon monoxide and Syngas (Hydrogen)

Pyrolysis Absence of oxygen Thermal degradation Liquid pyrolysis oil

Cont..

d. Carbon Rich Chain Platform : Transesterification “Biodiesel” Platform Takes vegetable oil, animal fat, or grease into biodiesel – fatty acid methyl ester Base catalyzed of the oil with alcohol, direct acid catalyzed, and conversion of the oil to fatty acids and then to alkyl esters with acid catalysts

Cont…..

3. Gasification How Does Biomass Gasification Work? Gasificationis a process that converts organic or fossil-based carbonaceous materials at high temperatures (>700°C), without combustion, with a controlled amount of oxygen and/or steam into carbon monoxide, hydrogen, and carbon dioxide. Biomass gasification is a mature technology pathway that uses a controlled process involving heat, steam, and oxygen to convert biomass to hydrogen and other products, without combustion. Because growing biomass removes carbon dioxide from the atmosphere, the net carbon emissions of this method can be low, especially if coupled with carbon capture, utilization, and storage in the long term. Gasification plants for biofuels are being built and operated, and can provide best practices and lessons learned for hydrogen production.

What is Biomass Gasification? Basic Process Chemistry Conversion of solid fuels into combustible gas mixture called producer gas (CO + H 2 + CH 4 ) Involves partial combustion of biomass Four distinct process in the gasifier viz. Drying Pyrolysis Combustion Reduction

Cont Biomass-Based Waste Materials Down draft Gasification System Syn gas Biochar Boiler, kiln to generate electricity Agricultural, Industrial Process Gasification Process

Types of Gasifiers Updraft Gasifier

Types of Gasifiers Downdraft Gasifier

Types of Gasifiers Twin-fire Gasifier

Types of Gasifiers Crossdraft gas producers

Biomass as Gasification Fuel Biomass: natural substance, storing solar energy as chemical energy by photosynthesis. Renewable and CO 2 -neutral Biomass chiefly contains cellulose, hemi-cellulose and lignin (av. composition C 1 H 1.6 O 0.8 ) Examples: wood, crop residues, animal wastes, sewage, and waste from food processing. Total combustion: 1 kg biomass + 6 kg air  CO 2 + H 2 O + ashes Gasification: 1 kg biomass kg air  CO + H 2 + CO 2 + tar + PM Most biomasses with moisture content of 5-30% can be gasified.

Gasification of biomass: where and why? Technology for providing affordable and competitive electricity supply and energy services to rural areas where agricultural and plantations wastes are available. Traditional ways of burning biomass: low efficiency, toxic emissions Typical gasification reactor: receives air and solid fuel and converts them into gas, followed by a cooling and washing train where the impurities can be removed. Final use of gas: Work: cleaned combustible gas used in diesel- generator sets in dual fuel mode Heat: producer gas-based engine generator (little or no purification needed) flame T up to 1200  C.

Performance of gasifier-engine system Efficiency in the production of producer gas: up to 70% at best. Efficiency of diesel and gasoline engines: 30% and 20% respectively. In practice, a power drop ranging from 25 % to 60 % can be expected when diesel or gasoline engine is run with producer gas

Difference between diesel and gasoline engine Diesel + air: auto-ignition Producer gas- air mixture does not auto-ignite, need to be co-injected with diesel fuel. In gasoline engine, producer gas + air can be ignited by the spark. (more convenient in remote rural areas)

Gasification Process Gasification: conversion of solid carbon fuels into COx/H 2 by a thermochemical process. Accomplished in a sealed chamber at ambient pressure.