Grad Studio II
Spring 2026
Instructors:
Hannah Chung, Peter Yeadon
Additional Inputs:
Scarlett Huo, Winnie Chou
Photography Assist:
Joyce Chen
Cafe is one of the few sites in contemporary consumer culture where production is performed in full public view, a place where coffee is ordered, prepared, and served as a visible sequence in which the ritual of making is as much a part of the product as the beverage itself. Yet the spent grounds displaced from the portafilter dozens of times each hour, exits the cycle immediately and without acknowledgment. Spent coffee grounds retain considerable chemical and energetic value and are nonetheless discarded as a matter of routine. They are also a waste stream with an unusually legible point of origin: the machine responsible for their production is present and thermally active at the precise moment the waste is created. That condition of proximity presents a design opportunity that existing appliance typologies have yet to seriously address.
Spent coffee grounds represent one of the most consistently underaddressed organic waste streams in the modern food service industry. Globally an estimated 15 million tonnes are generated annually, with commercial sources including cafes, restaurants, and cafeterias accounting for approximately half of that figure. Despite this scale, the material is treated almost universally as residue: collected, bagged, and landfilled with little to minimal consideration of its chemical compositions or energetic potential.
Organic material deposited in anaerobic landfill conditions produces methane, a greenhouse gas with a global warming potential significantly higher than CO₂ on a 20-year timescale. That a material so consistently and predictably generated has attracted so little design attention at the point of production, rather than downstream in composting initiatives or industrial upcycling programs, points to a structural gap in how appliance design frames its own material responsibilities. This project situates itself within that gap, proposing that the site of waste generation and the object responsible for it are can be joined together in harmony.
The design process originated with an investigation into the constituent stages of the pyrolysis reaction and the conditions under which the process could be scaled from sustained industrial infrastructure to an appliance-sized reactor. A critical early finding was that pyrolysis is time and distance dependent: adequate thermal decomposition requires that feedstock travel through sustained heat over a meaningful dwell path. This constraint became the primary generative problem of the project. In response, a series of spiral feed mechanisms were developed to maximize the internal travel distance of spent coffee grounds within a compact reactor volume, ensuring that the material undergoes progressive drying and superheating while remaining in continuous motion through the chamber. The resulting object is resolved as a two-sided design: the front face functions as a conventional espresso machine, the site of coffee preparation and customer interaction, while the rear houses the pyrolysis reactor, the site of waste processing and material transformation.
Establishing pyrolysis reactor logistics, and integrating espresso machine design layout in diagram form.
Study on positioning of spiral feeders, original idea calls for the pyrolysis reactor to coexist with the espresso machine on a single side.
Establishing various components required for both coffee brewing and grounds post-processing.
Preliminary design of the espresso machine handle and mechanisms.
Extended study of various handle and portafilter configurations.
Pyrolysis chamber feeder preliminary study. Design of heating element.
Dual barrel pyrolysis chamber design, outside barrel facilitates heating, while inside barrel feeds the grounds and slowly converts into biochar and syngas without burning them.
A portion of syngas is reintroduced from the inner back to the outside barrel to recycle the heat, promoting a self-sustaining reaction as pyrolysis reactors reach desired temperature.
Overall apparatus design and initial prototyping.
Finalized design of espresso machine and pyrolysis reactor, dimensions established.
The formal language of the machine draws from industrial and automotive precedents, specifically the visual and structural logic of combustion systems in which gases, fluids, and heat move through a series of discrete but interdependent components. The aesthetic sensibility of the project is grounded in that tradition: the Mercedes-Benz SL65 AMG Black Series, manual espresso machines, and precision lathe equipment each contributed to an understanding of how high-performance mechanical objects resolve complexity into coherent, legible form.
Common to these references is a design culture that does not conceal its own workings, but instead treats functional density as an aesthetic condition in itself. Materially, the machine is conceived in steel and aluminum, selected for their thermal tolerance, structural integrity under sustained high-temperature operation, and formal compatibility with the industrial register the project occupies.
