Biogas Recovery: A Renewable Energy Source for Generating Steam

The growing drive within corporations to become more sustainable has led to increased research into clean, renewable energy sources that can help mitigate greenhouse gas (GHG) emissions. Organic waste like plant residue, food waste, and agricultural or livestock waste is already being reclaimed to create a cost-effective, renewable energy source known as biogas. Recovered and cleaned biogas can be used as an alternative fuel source or additive to natural gas to provide thermal (heat) energy or generate electricity.

Biogas recovery can help reduce expenses, increase efficiencies, and help lower GHG emissions for manufacturers, paper, textile, and food processing plants that generate a significant amount of organic waste.

Fighting Pollution: NonProfits, Programs, and Policies

US federal and state governments and private businesses are realizing the need to work proactively towards protecting the planet against harmful emissions and unsustainable production procedures. In a bold statement to support the fight against the environmental crisis, the founder of Patagonia, Inc., Yvon Chouinard, announced he would transfer 98 percent of ownership and 100 percent of nonvoting stock to a nonprofit, Holdfast Collective. Any excess company profits will be distributed as a dividend to the Collective to be used to combat greenhouse gas emissions.

The 2022 Inflation Reduction Act (IRA), recently passed by Senate, authorizes approximately $370 billion for energy security and climate programs that help address pollution issues. The bill provides tax credits and grants for clean energy manufacturing and electricity production from renewable energy sources such as geothermal, solar, hydropower and biomass.

It includes a Methane Emissions Reduction program to financially incentivize the petroleum and natural gas sectors to lower methane emissions while penalizing facilities with a fee if they exceed methane waste emissions thresholds. The program further supports innovations that help limit methane pollution.

On the ground, several US states and cities have organic recycling policies that mandate that “large waste generators” recycle organic waste material through biogas or compost systems. In addition, over 2,000 sites across the US currently use biogas systems to capture methane gas from livestock waste, food waste, and landfill gas to produce biogas – a renewable substitute for natural gas – and reduce GHG emissions.

Through a collaborative sponsorship program called AgSTAR, the US Environmental Protection Agency (EPA) and the United States Department of Agriculture (USDA) now look to increase this number to 11,000 to help meet US renewable energy goals.

Biogas Recovery: An Overview

In biogas recovery, a green technology known as anaerobic decomposition is used to break down organic waste, animal waste, and even industrial and commercial waste matter into water vapor, methane, carbon dioxide (CO2), hydrogen, hydrogen sulfide (H2S), and its residual material, or digestate.

During the decomposition process, this waste (or biomass) is placed inside an airtight container called an anaerobic digester, where microorganisms eat and digest it. The resultant biogas is then captured and cleaned by removing water, CO2, H2S, and other trace elements to create pure methane. The digestate can be used as a fertilizer. At the same time, the upgraded biogas is co-burned with natural gases inside fuel-burning equipment (like a boiler or gas turbine engine) to help reduce fossil fuel consumption and emissions.

The Business Case for Biogas Recovery

The American Biogas Council states that the thermal heat needed in industrial manufacturing is responsible for approximately 11% of US GHG emissions. Biogas recovery is one way for companies to reduce their carbon footprint and help reach net zero goals. It can also be good for business.

According to Ed Verderose, US National Accounts Manager at Miura, Inc., large facilities that generate substantial amounts of organic waste can take advantage of biogas recovery to reduce waste disposal costs and increase overall efficiencies.

“With a substantially high methane content (around 60%), biogas has a significant amount of heat (or calorific) value that would be otherwise wasted or disposed of,” explained Verderose. “If you are a manufacturer capable of repurposing your waste byproducts and turning them into clean energy, like biogas, then you’re going to make your product stream more efficient,” he added.

Verderose highlighted that, while biogas recovery is more expensive than using standard fossil fuels, repurposing organic waste material to introduce energy back into the production process can offset these costs.

“Right now, in everything that we do, we have to put more energy into it than we get out of it. People don’t often realize that it costs more money to make natural fuel from biofuel than it does to pull it out of the earth.

“However, if a facility can take its waste and turn it into energy that it perpetually consumes, then the process becomes more energy-efficient. You’re reducing that process’s overall energy cost and energy consumption by taking just one piece in your process and reintroducing it into the energy cycle. You won’t just be getting rid of the refuse; you’ll be turning it into a revenue stream while still meeting environmental mandates.”

Can Miura Steam Boilers Use Recovered Biogas?

Miura prides itself on equipping facilities with energy-efficient boilers that match fluctuating load demands and help reduce their carbon footprint. “We like to partner with manufacturers so that we can look at their throughput and workflow and give them ideas on how to use their energy a little bit better,” explained Verderose.

Miura’s EX series Dual Fuel burners are ideally suited to burn renewable natural gases like recovered biogas and already achieve NOx ratings as low as 30ppm, depending on the model. Natural gas, propane, or #2 Fuel Oil can be used as a backup fuel where a secondary fuel source is required.

“The Miura boiler that likes to burn biogas the most is Miura’s EX boiler,” shared Verderose. “It’s got a nice big furnace volume, giving it plenty of time for the fire to mix with and burn the constituents of the biogas. It handles the impurities and the combustion of the fuels well. Miura has those throughout the world right now, including the US.”

Miura’s Sustainable Steam Solutions

A global industrial boiler manufacturer, Miura, Inc., is committed to developing steam solutions for various industries to help them reduce greenhouse gas emissions and increase efficiencies. Contact a Miura rep today to discuss how our low NOx steam boiler solutions can help you be more energy-efficient while reducing your carbon footprint.