The ZooPoo Process

by Mark Edwards

ZooPoo includes the liquid and solid the wastes from animals, plants and zoo trash. The exhibits will use about 60% virtual – videos, and 40% interactive. Waste-to-energy videos will provide guests with sights of amazing processes using big screens that avoid the required footprint, odors and the noise. The interactive exhibits will entertain and engage target guests of all ages.

ZooPoo employs a clean and adaptable carbon-neutral production process that consumes large amounts of CO₂ and transforms the carbon into high-value products while releasing pure oxygen into the atmosphere. ZooPoo uses abundant, (renewable) or surplus inputs while producing valuable products and pollution solutions. ZooPoo biosolids will be filtered, dried in the sun and then burned in a closed kiln in a process called pyrolysis. Burning the organic matter in the closed system releases no CO₂ to the atmosphere and creates three valuable components: H₂, CO gases and biochar.

The ZooPoo process. (Click image to enlarge).

The H₂ is piped to a generator to create more electricity for the ZooPoo exhibit. The carbon monoxide gas is piped to an algae pond where it provides the carbon for additional algae production. The biochar is sold to farmers as a slow release biofertilizer and soil conditioner.

The core carbon neutral technologies provide a showcase for abundance. Carbon neutral production means that no new carbon enters the atmosphere. Abundance production methods insure that no, or minimal, fossil resources are consumed in production by using several biotechnologies.

• Nutrient recovery – algae bioaccumulate and store nutrients from the poo tea created from animal and plant waste streams.
• Energy recovery – burning animal and plant solid wastes in a closed system, gasification or pyrolysis, creates H₂ for energy production and more CO and CO₂ to feed algae.
• Clean water – algae clean wastewater and make it suitable for irrigation, animal or human use. Wastewater treatment is the oldest algae application in the US and dates back 70 years.
• Energy production – algae are harvested, and the oil is pressed out to create clean, green diesel that burns with no black smoke particulates. Additional energy is created by the H₂ produced from gasification of solid wastes.
• Biofertilizer – selected residual from algae production may be used as a fertilizer for the many plants at the zoo. Biochar, a byproduct from pyrolysis waste management, will provide additional fertilizer and soil amendment for Zoo plants. Some local algae will be grown as liquid biofertilizer for drip systems in greenhouses and in hydroponic production of vegetables.
• Biofeeds – high protein algae cultivars will be grown for animal feed. Most animals will receive a mix of algae and food grains, or in the case of carnivores, meat. The aquaponics exhibit will display fish eating repurposed nutrients in their algae diet.
• Farmaceuticals and medicines – algae compounds are harvested to make animal health foods, vitamins and minerals, including omega-3 fatty acids, which improve the health of zoo animals.

Carbon neutral production

The ZooPoo algae production system (above) illustrates the steps in carbon neutral production where fuel, electricity, food, feed, fertilizer and other products are made using no or minimal fossil fuels or fossil carbon products such as fertilizers or agricultural chemicals. The algae may be harvested and processed to create biodiesel, high-protein feed, carbohydrates, biofertilizers and a host of other products. Carbohydrates may be converted to ethanol, paper or textiles.

ZooPoo may not be pretty in a classic sense, because waste streams are dirty. The ZooPoo mantra will show in various ways how recycled nutrients can create bioproducts that are clean for people, animals, plants and our environment. Critically, the exhibit will smell good because released orders indicate a waste of valuable nutrients.

ZooPoo will turn poo upside down and celebrate poo as a treasure that transforms brown into gold; clean, green food and energy. Exhibits will demonstrate steps in the process to assure cleanliness, healthiness and nutrient value. There will be many examples of how poo is used globally, such as China’s farmers that have used human poo on their fields successfully for thousands of years. Organic farmers use animal waste regularly on their fields to produce healthy crops. Students may not know that beer and wine come from the excrement of yeast cells, or that the Plains Indians, as well as early settlers used buffalo poo regularly for their cooking fires. Poo retains high-value energy and nutrients, why waste it?